Collapsible drill bit



March 9, 1937'. P K|NNEAR 2,073,279

coLLAPsIBLE DRILL EIT Filed May 4, 1933 4 Sheets-Sheet 1 March 9, 1937. L, P, ,(.NNEAR 2,073,279

COLLAPSIBLE DRILL BIT Filed May 4, 1933 4 sheets-sheet 2 I ll I I FFI-T77 nlllgl March 9, 1937. P. KINNEAR coLLAPsIBLE DRILL BIT Filed May 4, 1933 4 Sheets-Sheet 3 H s m4n/@Mu 311W .ma E@ m, W. w/ .a WanA UM mm U, 1 7

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L. P. KINNEAR COLLAPSIBLE DRILL BIT March 9, 1937,

Filed May 4, 1933 4 Sheets-Sheei 4 .fm/MMR 35M/@Mm M/ Patented Mar. 9, 1937 UNITED STATES PATENT VOFFICE 2,073,279 ooLLAPsmLE DRILL Brr Leland Paul Kinnear, Beaumont, Tex.

Application May 4, 1933, Serial No. 669,418

23 Claims. (Cl. Z55- 74) The invention relates to new and useful improvements in a collapsible bit for drilling deep wells, such as oil or artesian wells.

An object of the invention is to provide a means for supporting the bits so that they may be attached to a holding chuck at the bottom of the well through the aid of fluid pressure on the iiushing water.

A further object of the invention is to provide a detachable bit construction of the above type with a supporting means for the bits, whereby the bits may be bodily shifted laterally to seated position in the chuck by wedge bars which serve as a positive locking means for holding the bits in an operating position o'n the operating chuck.

A further object of the invention is to provide -a detachable bit construction of the above typea wherein the bits are provided with rounded inclined shoulders seated in similar shaped recesses formed in the chuck.

Another object of the invention is to provide a detachable bit construction of the above type, wherein the chuck is provided with rounded surfaces contacting with the shanks of the drill bits and the wedge bars, some of which are eccentric and serve to impart positive rotation to the bits when said chuck is rotated.

A still further object of the invention is to provide a drilling bit which is so constructed that the wearing away of the operating edge thereof will produce new cutting edges of substantially normal thickness. y

These and other objects will in part be obvious and will in partfbe more fully disclosed. In the drawings, which show by way of illustration one embodiment of the invention:

Figure 1 is a vertical sectional view through the lower portion of the chuck showing the bits and the lower supporting head therefor in side i0 elevation.

Figure 2 is a similar view of the upper portion of the chuck and showing the upper head for supporting the bits, and also the supporting member for the wedge bars, said parts being in side elevation.

Figure 3 is a side elevation of the wedge bars and the supporting head therefor.

Figure 4 is a'n end view of the supporting head for the wedge bars, thelview'being taken on the line 4 4.

Figure 5 is a sectional view of the lower portion of the ch ck showing the bits as detached` from the chuck and partly raised therefrom. Figure 6 is a similar view of the central portion of the chuck withthev bits positioned as shown in Figure- 5.

Figure 7 is a vertical sectional view through the upper portion of the chuck and the pipe section to which it is attached also showing the `bits 5 in the position shown in Figure 5.

. Figure 8 is a vertical sectional view through the operating pipe casing at the surface end of the well and showing the sealing of the pipes and the manner of supplying flushing water thereto. 10

Figureri) is 'a vertical sectional view through the upper end of the pipe easing showing the sealing head removed and the drilling bits raised to the upper end of the pipe casing by a grabhook preparatory to the removing of the bits 15 from the pipe casing.

Figure 10 is a sectional view on the line lli- I0 of Figure 9. Figure 11 is a side view of the grab-hook with the wedge blocks removed and the head de- 20 tached.

Figure 12 is a sectional view on the line |2--I2 of Figure 11.

Figure 13 is a face view of one of the wedge blocks used in connection with the grab-hook. 25

Figure 14 is an edge view of the wedge block.

Figure 15 is a sectional view on the line l5-I5 of Figure 1 with the drilling bits in place on the chuck. y

Figure 16 is a sectional view on the line IB-IG 30 of Figure 5 with the drilling bits removed.

Figure 17 is a similar sectional view on the line I'l-I1 of Figure 5.

Figure 18 is a sectional view on the line l8-i8 0f Figure 6. 35

Figure 19 is a sectional view on the line I9-I9 of Figure 3.

Figure 20 is a. detail showing the lower end of the chuck with the bits seated and in side view.

Fig. 21 is a sectional view on the line 2I-*2l of 40 Fig. 6. l

The invention is directed to a drilling appa-f ratus which includes a supporting chuck I3 attached to the lower end of a pipe casing 56 extending from the bottom of the well to the sur- 45 face, which pipe casing is operated for rotating the chuck. A removable drill bit assembly is lowered through the casing and into the chuck by a cable, and this drill bit assembly carries the drill bits winch are attached to the chuck for 50 operation, and may be detached therefrom and removed from the casing. 'I'he drill bit assembly includes a supporting head Il and the drill bits are attached thereto by flexible members I0 that each drill bit is capable of bodily lateral 55 movement to and from seating position on the chuck. The supporting head for the drill bits not only includes a lower head member I I but also an upper head member 20 which is spaced 5 therefrom and rigidly connected thereto by rods I9. Mounted for sliding movement on the rods is a head 2I carrying wedge bars I6, I6 which, when moved downwardly, engage the shanks of the bits and force the same laterally for the seating of the bits on the chuck. The head supporting the wedge bars and the bars are provided with continuous passages Il for flushing water. Attached to this head carrying the wedge bars is a spear head body 26. The cable through a grab hook is attached to the spear head body. This head carrying the wedge bars is packed so as to contact with the casing and the ushing water can only pass through the flushing-passages extending down through the head and wedge bars. The grab hook 40 for lowering the drill assembly into the chuck is provided with valve rods I2 which are placed in these flushing passages when the grab hook is attached to the assembly for closing the same. These valve rods remain within and close the u'shjng passages until the grab hook is released and retracted. During the lowering of the drill bit assembly, the flushing water bears on the head carrying the wedge bars and it engages the head member II carrying the drill bits and forces the drill bit assembly downwardly through the casing and through the chuck to position for seating the bits. When the drill bits reach their lowered position, further downward movement ceases, and the ush- 3.5 ing water pressing on the head carrying the wedge bars will positively force the wedge bars downwardly along the shanks of the bits, thus forcing the bits to seated position on the chuck, so that the ushing water is utilized not only for the 40 forcing of the drill bit assembly into the chuck, but for moving the drill bits on the assembly into seated position. When the grab hook is released and raised, it carries with it the valve rods, so that the flushing openings are opened and ushing water can flow freely therethrough.

It is thought that the invention will be better understood by a detailed description of the present illustrated embodiment thereof. The drill bits are similar in construction and each bit includes a blade I carried by a shank portion 6. 'Ihe shank portion 6` has flat sides indicated at 'I in Figure 15 and rounded faces indicated at 8. The blade I of the bit, Where it joins the shank, is provided with a rounded inclined shoulder 5.

Each bit blade has recesses 2, 2 formed in the outer face thereof, and at a slight distance above these recesses are similar recesses 3, 3. Each recms has its upper face substantially horizontal and its inner faceinclined so that when the lower cutting face of the bit blade wears away. the bit i will resharpen itself. In other words, when the blade is worn away to the recess 2 there will be sections of the same initial or normal thickness which become the cutting edges. Likewise, when the bit wears away to the recesses 3 the cutting edge will be again reduced to the normal initial thickness in the region of these recesses. On the bits may be attached to this chuck for operation and detached therefrom without withdrawing the chuck and the pipe sections from the well.

The shanks E, 6 of the drill bits are carried by a supporting unit which includes a lower head member I I and an upper head member `2li. These head members are rigidly connected together by rods I9. The rods are threaded and screwed into the head II. These rods are provided with shoulders to engage the under face of the head 20, and nuts 33 are threaded onto the rods thus rigidly attaching the two heads I I and 20 together as a unit. The shanks 6 have bushings 9 secured in the upper ends thereof and the cables I0 extend into the bushings and are leaded therein. There are also bushings I2 in the lower head II and the cables extend into these bushings and are leaded therein. This makes very rm but flexible connections between the shanks and the supporting head II. This supporting head II is of substantially the same diameter as the interior of the pipe sections and the upper portion of thechuck so that it has little or no lateral movement therein, but is free to be movedendwise thereof. 'Ihe drilling bits may, however, be moved bodily laterally of the chuck, either to seated or unseated position, due to the flexible cable connections which attach the drill bitsto the lower head II. The upper portion of the chuck I3 has an opening therethrough which is circular in cross section. 'I'he lower prtion of the chuck where the drilling bits are seated has spaced curved surfaces which are concentric with the longitudinal axis of the chuck and joining curved surfaces which are eccentric with the longitudinal axis of the chuck. These concentric surfaces are indicated at I3e in Figure 16 and the eccentric surfaces are almost straight and are indicated at I 3f. Extending between the chamber at the upper end of the chuck which is circular in cross section, and the chamber at the lower portion of the chuck having the eccentrically curved sides, is an inclined tapering-oil' Wall indicated at I 3d. The purpose of this tapering-olf wall I3d is to cause the drilling unit to properly aline itself for entrance into the lower part of the chuck. If the shanks of the drilling units are properly positioned so that they will be opposed to the circular or concentric surfaces, then the drilling unit will slip down into the lower part of the chuck. If, however, they are not so positiored, the blades are so constructed that they will contact with this tapering-oir wall I3d, and this will turn the unit so that it will properly enter the lower part of the chuck and be properly sealed when the wedge bars are lowered in the curved cut-away portions I3b. The tapered portion`I3d terminates at the shoulder I4 and is inclined for the purpose 'of centering and directing the drill bits as has just been described. When the wedge bars and drill bits are seated on the chuck, they contact with these curved surfaces and eccentric surfaces so that' the unit throughout the entire circumferential extent contacts with curved faces, and this prevents any tendency of the shanks to burr or cut the walls of the driving chamber of the chuck during the turningpf the chuck for the operating of the drilling bits.

The lower end of the chuck is provided with two recesses I3b, one of which receives the rounded inclined shoulder 5 on one of the drill bits, while the other recrlves the rounded inclined shoulder of the other drill bit. When the drill bits are lowered into the chuck so that the blades are beneath the chuck they may be forced laterally and cause the inclined shoulders to seat in these recesses I 3b|3b respectively. It is noted that these shoulders are rounded, and this prevents any burring of the edges which would prevent the proper seating of the bits. Surrounding the lower portion of the chuck is a steel casing |3c. This steel casing strengthens the lower portion of the chuck which is under the strain of turning the bits and prevents the chuck from splitting.

The bits are positively seated and locked in position on the chuck by wedge bars |6-I6, one for each bit shank. These wedge bars are carried by a supporting head 2|. The supporting head 2| is provided with openings |90. and the rods I 9 extend through these openings so that the head 2| is free to slide on the rods I9. There are passages |1 through the head 2| and extending all the way through the wedge bars for flushing water. The head 2| is provided with annular recesses 24a in which are placed gaskets or packing members 24. These gaskets contact with the inner faces of the chuck after the head 2| passes the shoulder Ila. in the chuck and it seals on the chamber to the lower part of the chuck from the chamber at the upper part of the chuck. There is also a gasket disk 26, at the upper end of the head 2| which is held in place by rods I9, and slides on said rods the same as head 2|, and steel plate 29. Threaded into the head 2|, centrally thereof, is a sleeve 25 which is used for lifting the head carrying the wedge bars. This sleeve extends upwardlly through an opening in the upper head 20 and is threaded into the lower .end of the spear tube body 26. This iirmly connects the spear head 26 to the head 2l carrying the wedgel bars, and when the drilling unit is supported-by the grab-hook attached to the spear head the head 2l carrying the wedge bars will slide upwardlly on the rods I9 until a collar 3|) attached to the sleeve 25 contacts with the under face ofthe head 20.

Threaded into the head 2| and in alnement with the flushing passages I1 are short pipe ends 21, 21. These pipe ends terminate below the upper face of the collar 30. The tool unit is lowered into the casing by a grab-hook or releasable tool holder 40. This tool holder is in the form of a sleeve having openings Il through the walls thereof. These openings are tapered at the upper and lower ends thereof. Wedge blocks 39 extend through the openings Il,

These wedge blocks are adapted to engage beneath shoulders 35 on the spear head 26. The wedge blocks are carried by a locking stem or piston 36 which is provided with a head 38e beneath which the section of the stem 38a is of slightlyv less diameter, and beneath this section 38a. is a section 33h of still less diameter. It will be apparent that if the stem is raised so as to bring the section 38h opposite the wedge blocks- 39 that they are free to move inwardly so as to be released from the shoulder 35. This stem, which locks the wedge blocks, has a del pending rod section 33d which is adapted to contact with a trip rod 23. The trip rod 23 extends down through the sleeve 25 connecting the spear head to the wedge bar supporting head 2|, and also through an opening 22 in the head 2l and down into the wedge bars until it engages a shoulder |3a'on each wedge bar. The trip rod normally Y rests VVom these shoulders during the lowering of the drilling unitthrough the well casing. The .rod extends up through the sleeve 25 and the stem 38d will bear against the upper end of the rod at this time (see Fig. 7). Attached to the grab-hook or tool holder 40 are valve rods 42. These rods pass through openings 43 in the spear head and also openings in the upper head 20 and into the pipe sections 21. When the drill unit is being suspended and lowered into the pipe sections by the grab-hook or tool holder, this closes the flushing passages through the head 2| and the wedge bars. The packing carried by the head 2| prevents the flushing water from passing by the same when it reaches the chuck, and therefore the iluid pressure of the flushing water will force the drilling unit into the chuck and position the drilling bits ready for seating. When the drilling unit reaches this position the lower head Il contacts with the shoulder Il on the chuck which limits the downward movement of the lower head II and also the upper head 20 which support the drilling bit. The fluid pressure, however, bearing on the upper end of the head 2| carrying the wedge bars will force the wedge bars on down alongside of the shanks of the drilling bits, and this will force the shanks bodily laterally and cause the drilling bits to be seated and locked in seated position. It is not only the weight of the supporting head for the wedge bars and the spear headwhich is. forcing the wedge bars downward, but the fluid pressure bearing against the upper end of the head 2|, due to the fact that the valve rods are operating to close the flushingpassages. The lower ends of the wedge bars .are tapered on one side as indicated at |6a and on the other side as indicated at |617. The

tapered surface lia is relatively long and when the wedge bars are brought into engagement with the upper'ends of the Shanks s, s of me respective bits, as shown in Figure 5, they will pass down along the bit shank and force the same laterally so as to seat the bits. 'I'he trip rod rests on the shoulders |8a of the wedge bars until these shoulders pass down into the head The rod then contacts with the upper end of the head I| and stops its further downward movement. As the spear head and grab-hook continues its downward movement, the stem or piston 33 resting on the upper end of this trip rod` 23 will stop its downward movement, and this will',cause the section 38h to be positioned op'- posite the dogs or wedge blocks 39 releasing the same so that the beveled shoulder acting on the wedge blocks will cause the same to be released from the spear head. Assoon as the grab-hook is released from the spear head the operator can lift the same. The lifting of the grab-hook will raise the valve rods 42 and open the ilushing passages so that the pressure on the ushing water will be released, and this will indicate to the operator that the drilling ibits are seated and the grab-hook or tool holder' is released therefrom. The trip rod cannotrelease the wedge bars from the supporting engagement of the spear head until the shoulder ||a on the head contacts with the shoulder I6 on the chuck, and the wedge bars have moved downward to their full seated position. The piston or stem 38 will begin its movement when the rod 23 contacts with the head Il but it will not be moved.

dogs may be reached through these openings and properly adjusted when the grab-hook is fastened to the spear head. Draining openings 34 are also provided at the lower end of the spear head.

The grab-hook or tool holder 40 is attached to a head 40a having a bail, and the cable 41 is passed through the bail formed into a single loop knot, and the end thereof is clamped by a clamping member 55. This cable 41 passes through a circulating head 46. A cap 48 is threaded onto the head, and packing gaskets 45 are located in a recess in the cap 48. A steel plate 59 contacting with the shoulder on the circulating head bears against these gaskets, and thus a uid tight joint can be made between the circulating head and the cable which allows the cable to freely move as the drilling unit is lowered through the pipe sections into the chuck. The pipe 44 extending through the wall of the circulating head serves as a connection for the ushing water which is forced into the head under pressure. The line 58-58 indicates the 'earth surface.

The tool holder or grab-hook 40 which has been described is used particularly for lowering the drill unit throughthe pipe sections into the chuck and is releasable therefrom in a manner which has been described above. A fishing grab-hook for removing the drilling units is'shown in Figures 9 to 14 inclusive. It consists of a shank member 52, at the lower end of which is a head 49. Intermediate the head and the shank member is a wedge supporting body member 52a.

" Said body member is tapered and hasdovetailed grooves in the side faces thereof in which are mounted wedge dogs 50, 50. Surrounding the stem 52 is a sleeve 5|. A spring 53 bears against the upper end of the sleeve and against the head 54 to which the cable 41 is attached. This sleeve 5I normally forces the wedge members downwardly on the body portion 52a and will force said dogs or wedge members outwardly radially so that they contact with the shoulders 35. At

, the upper end of the spear head there is a beveled shoulder 36 and the lower end of the head 49 is tapered. The operator lowers this grab-hook and nally centers the same so that it passes down into the spear head. The wedge blocks or dogs 50 are yieldingly forced to seated position, and as soon as they pass beneath the shoulder 35 they will contact therewith and serve as means for lifting the spear head 26. When the spear head 26 is lifted it will raise first the head 2| carrying the wedge bars, and this will withdraw the wedge bars from their locking position relative to the shanks of the bits. As soon as the Wedge bars are released the drilling bits are also released, and as the shoulders 5 are inclined a pull on the drilling unit through a further pull on the cable 4T will cause the drill bits to be drawn into the chuck and lifted from the chuck.

It is believed that the manner of attaching and detaching the drill bits has been clearly described in connection with the different features of structure cooperating with the drill bits for supporting and seating the same. It will be apparent from the above -description that a very simple means has been provided whereby fluid pressure on the flushing water may be utilized for positively forcing the drilling unit into the chuck and into a position fto be seated therein, after which fluid pres-sure positively forces the wedge bars intoplace, and as the wedge bars are finally seated the tool supporting means or grab-hook is automatically released through the action of the trip rod. As soon as the grab-hook or tool holder is released from the spear head the grab-hook may be raised withdrawing the valve rods from the flushing passages, and this is a signal to the operator that the bits are fully seated and locked in place, and therefore the grab-hook can be removed. When the drill bits are seated on the chuck they are not only positively held in place but they may be positively rotated through the curved sides of the chuck contacting with the curved faces of the shanks supporting the drill bits. As the drill bits wear away new cutting surfaces are produced, and said bits are in a measure self sharpening.

It is obvious that many changes in the details of construction and the arrangement of the parts may be made without departing from the spirit of the invention as set forth in the appended claims.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent is:-

1. A drilling apparatus comprising a chuck, pipe sections attached thereto for rotating the chuck, a drill bit assembly adapted to be seated in said chuck including drill bits and means whereby fluid pressure on the flushing water may be utilized for moving the drill bit assembly into said chuck and for moving said drill bits into seated position on said chuck, and a sealing head adapted to be attached to the upper end of the pipe sections and having a packed guideway therethrough for a lowering cable whereby said drill bits can be lowered into the chuck without breaking the seal, said head having means whereby fiushing water under pressure may be discharged into the pipe sections.

2. A drilling apparatus comprising a chuck, pipe sections attached thereto for rotating the chuck,and a removable drill bit assembly adapted to be seated in said chuck including drill bits, wedge bars for positively moving said drill bits to seated position on the chuck, and means whereby the fluid pressure on the iiushing water may be utilized for forcing the drill bit assembly into the chuck and for moving the wedge bars for forcing the bits into seated position on the chuck.

3. A drilling apparatus comprising .a chuck, pipe sections attached thereto forv rotating the chuck, a removable drill bit assembly adapted to be seated in said chuck including drill bits, said bits having curved side faces and said chuck at the lower end thereof having corresponding curved portions with whichv the curved faces of the shanks may contact for positively rotating the bits with the chuck, and means whereby iluid pressure on the flushing water may be utilized for forcing said bit shanks laterally into seating engagement with Athe curved portions on said shanks.

4. A drilling apparatus comprising a chuck, pipe sections attached thereto for rotating the chuck, a removable bit assembly adapted to be seated in said chuck including drill bits having shanks provided with curved outer faces, said chuck in horizontal section having spaced concentric surfaces conforming to and contacting with the curved faces on the shank when said bits are seated, said concentric surfaces on the chuck being joined by eccentrically curved surfaces for positively rotating the bits with the chuck, said chuck having interiorly thereof above said ,eccentric surfaces tapering eccentric portions contacting with the bits for pomtioning the same for proper engagement with the curved surfaces therebelow.

5. A drilling apparatus comprising a chuck,

Vpipe sections attached thereto for rotating the chuck, a removable bit assembly adapted to be seated in said chuck including drill bits having shanks provided with curved outer faces, said chuck in horizontal section having spaced concentric surfaces conforming to and contacting with the curved faces on the shank when said bits are seated, said concentric surfaces on the chuck being joined by eccentrically curved surfaces for positively rotating the bits with the chuck, said chuck having interiorly thereof above said eccentric surfaces tapering eccentric portions contacting with the bits for positioning Athe same for proper engagement with the curved surfaces therebelow, and means whereby iluid pressure .on the flushing water may be utilized for seating the bits on` the chuck.

6. A drilling apparatus comprising a chuck, pipe sections attached thereto for rotating the chuck, a removable drill bit assembly adapted to be seated in said chuck, said drill bits including blade portions and shank portions carrying the blades, each blade portion having a rounded inclined shoulder adjacent the shank adapted to seat in a correspondingly shaped recess at the lower end of the chuck,said chuck having eccentric surfaces for turning the bits with the chuck.

'1. A drilling apparatus comprising a chuck, pipe sections attached thereto for rotating the chuck, a removable drill bit assembly adapted to be seated in said chuck, said drill bits including blade portions and shank portions carrying the blades, each blade -portion having a rounded inclined shomder adjacent th shank adapted to seat in a correspondingly shaped recess at the lower end of the chuck, said chuck having eccentric surfaces for turning the bits with the chuck, and wedge 'baars for forcing said bits laterally to causez'sai'd shoulders to engage said recesses and for "holding said bits seated on the chuck.

8. A drilling apparatus comprising a chuck, pipe sections attached thereto for rotating the chuck, a removable drill bit assembly adapted to be seated in said chuck, said drill bits including blade portions and shank portions carrying the blades, each blade portion having a rounded inclined shoulder adjacent the shank adapted to seat in a correspondingly shaped recess at the lower end of the chuck, said chuck having eccentric surfaces for turning the bits with the chuck, and means whereby fluid pressure on the flushing watermay be utilized for seating the bits on said chuck.

9. A drilling apparatus comprising a chuck, pipe sections attached thereto for vrotating the chuck, a removable drill bit assembly adapted to be seated in said chuck, said drill bits including blade portions and shank portions vcarrying the blades, each blade portion having a rounded inclined shoulder adjacent the shank adapted to seat in a correspondingly shaped recess 'at the lower end of the chuck, said chuck Ahaving eccentric surfaces for turning the bitswith the chuck, and means whereby fluid pressure on ,the ushing water may be utilized for seating the bits on said chuck, said 'chuck having tapering at portions above the curved sections for positioning said bits so that they will enter between curved sections at the lower portion of 75 the chuck.

10. A drilling apparatus comprising a chuck, pipe sections attached thereto for rotating the chuck, a removable drill boit assembly adapted to be seated in said chuck including drill bits, each drill bit being provided with a cutting blade and -a supporting shank, a head adapted to slide into a packing for preventing flushing water from bypassing said head, said head carrying the wedge bars being slidably mounted on the head carrying the bits, a grab-hook adapted to be connected to the head carrying the wedge bars for lowering the same and the drill bits into the chuck and valve rods carried by said grab-hook for closing the :flushing passages during the lowering of the drill bits whereby fluid pressure on the ushing water may be utilized for seating the bits and placing the wedge bars.

11. A drilling apparatus comprising a chuck, pipe sections attached thereto-for rotating the chuck, a removable drill bit assembly adapted to be seated in said chuck including drill bits, each drill bit being provided with a cutting blade and a supporting shank, a head adapted to slide into the upper portion of the chuck, means for connecting said shanks to said heads whereby said bits may be bodily. moved laterally, wedge bars for seating the bits on said chuck, a head supporting the wedge bars and having flushing passages extending through the head and the wedge bars, said head carrying the wedge bars having a packing for preventing flushing water from by-passing said head, said head carrying the wedge bars being slidably mounted on the head carrying the bits, a grab-hook adapted to be connected to the head carrying the wedge bars for lowering the same and the drill bits into the chuck and valve rods carried by said grab-hook for closing the flushing passages during the lowering of the drill bits whereby fluid pressure on the ushing water may be utilized for seating the bits and placing the wedge bars, and automatic means for releasing the grab-hook from the head carrying the wedge bars when said wedge bars are in seated positon.

12. A drilling apparatus comprising a chuck, pipe sections attached thereto for rotating the chuck, a removable drillbit assembly adapted to be seated in said chuck including drill bits, each drill bit being provided with a blade and a supporting shank therefor, a head for supporting said bits including upper and lower head members, rods rigidly connecting said upper and lower head members, wedge bars slidable through said lower head and a supporting head for the wedge bars sliding on said rods, a spear head located above the upper head carrying the drill bits, said spear head being connected to the head supporting the wedge bars whereby the spear head will support the wedge bars and through the head carrying the wedge bars will support the drill hits for lowering the same into the chuck.

13. A drilling apparatus comprising a chuck, pipe sections attached thereto for rotating the chuck, a removable drill bit assembly adapted to be seated in said chuck including drill bits, each drill bit being provided with a blade and alsupporting shank therefor, a head for supporting said bits including upper and lower 'head members, rods .rigidly connecting said upper and lower head members, wedge bars slidable through said lower head and a supporting head for the wedge bars sliding on said rods, a spear head located above the upper head carrying the drill bits, said spear head being connected to the head supporting the wedge bars whereby the spear head will support the wedge bars and through the head carrying the wedge bars will support the drill bits for lowering the same into the chuck, a grab-hook, supporting devices carried thereby for engagement with the spear head, a tripping member carried by the grab-hook for holding said devices in engagement with the spear head, a trip rod supported by the wedge bars and adapted to contact with the lower head carrying the drill bits when the wedge bars are approaching their full seated position and operating to trip the holding devices of the'grab-hook for releasing the same when said wedge bars are fully seated. f

14. A drilling apparatus comprising a chuck, pipe sections attached thereto for rotating the v chuck, a removable drill bit assembly. adapted td be seated in said chuck including drill bits, each drill bit being provided with a blade and a supporting shank therefor, a head for supporting said bits including upper and lower head members, rods rigidly connecting said upper and lower head members, wedge bars slidable through said lower head and a supporting/head for the wedge bars sliding on said rods, a spear head located above the upper head carrying the drill bits,

said spear head being connected to the head supporting the wedge bars whereby the spear head will support the wedge bars and through the head carrying the Wedge bars will support the drill bits for lowering the same into the chuck, a grabhook, supporting devices carried thereby for engagement with the spear head, a tripping member carried by the grab-hook for holding said devices in engagement with the spear head, a trip rod supported by the wedge bars and adapted to contact with the lower head carrying the drill bits when the wedge bars are approaching their fullV seated position and operating to trip the holding devices of the grab-hook for releasing the same when said wedge bars are fully seated, said head carrying the wedge bars having flushing openings therethrough and having packing devices contacting with the chuck for preventing the fiushing water from by-passing the head except through said flushing passages, and valve rods lcarried by the grab-hook and closing said flushing passages while the drill bits are being seated whereby fluid pressure on the iiushing water may be utilized for forcing the drill bits into the chuck and for forcing the Wedge bars to full seated position.

15. A drilling apparatus comprising a chuck, pipe sections attached thereto for rotating the chuck, a removable drill bit assembly adapted tol be seated in said chuck including drill bits, said drill bits being provided with blade portions and shank portions carrying the blades, each blade portion having rounded inclined shoulders adjacent the shank adapted to seat in correspondingly shaped recesses at the lower end of the chuck, and a steel jacket surrounding the lower portion of said chuck for strengthening the same.

16. A drilling apparatus comprising a drill stem casing, a chuck attached to said casing, a removable drill bit assembly adapted to be seated in said chuck including drill bits having cutting blades, wedge bars for forcing said drill bits to seated position on said chucks, a piston head supporting said wedge bars, said piston head having fluid passages extending therethrough and connecting with fluid passages in said wedge bars, a lowering device adapted to be connected to said drill bit assembly, said lowering device having means for closing said fluid passages whereby iluid introduced into said drill stem casing under pressure may be utilized for forcing said drill bit assembly through the casing and into said chuck and for forcing said drill bits into seated position on said chuck.

1'7. A drillingapparatus comprising a drill stem casing, having a chuck secured thereto, a removable drill bit assembly adapted to be seated in said chuck, a lowering device' adapted to be connected to said drill bit assembly including a body portion, holding dogs associated therewith, a central trip plunger having a large portion and a reduced portion, said large portion operating to hold the dogs in gripping relation with the 'drill bit assembly and the reduced portion of the trip plunger when associated with the dogs adapted to release the dogs from gripping relation with said drill bit assembly.

18. A drilling apparatus comprising a drill stem casing, a chuck attached to said casing, a removable drill bit assembly adapted to be seated in said chuck including drill bits having cutting blades, separate and independent wedge bars for forcing said drill bits to seated position on said chuck, a head supporting said wedge bars, said head having fluid passages extending therethrough and connecting with uid passages in said wedge bars, said iiuid passages in saidwedge bars being disposed so as to direct iluid to the cutting surfaces of the cutting blades.

19. A drilling apparatus comprising a drill stem casing, a chuck attached to said casing, a removable drill bit assembly adapted to be seated in said chuck including drill bits having cutting blades, separate and independent Wedge bars for forcing said drill bits to seated position onsaid chuck, a head supporting said wedge bars, said head having iiuid passages extending therethrough and connecting with uid passages in said wedge bars, said iiuid passages in said wedge bars extending for the entire length through said wedge bars for directing fluid to the front sides of the opposite cutting blades.

20. A drilling apparatus comprising a drill stem casing, a chuck attached to said casing, a removable drill bit assembly adapted to be Iattached to said chuck including drill bits having cutting blades and a shank associated with and supporting each cutting blade, a head, separate wedge bars lcarried by said head and operating on said Shanks for forcing the drill blades to extended position on said chuck and for maintaining said blades in extended position, said head having fluid passages extending therethrough and connecting with fluid passages in the wedge bars, said fluid passages in said wedge bars being disposed so as to direct fluid to the cutting surfaces of the cutting blades.

21. A drilling apparatus comprising a drill stem casing, a chuck attached to said casing, a removable drill bit assembly adapted to be attached to said chuck including drill bits having cutting blades and a shank associated with and supporting each cutting blade, a head, separate wedge bars carried by said head and movable along said shanks in contact therewith for forcing the cut:- ting blades to an extended position on said chuck, said wedge bars contacting with said Shanks throughout the greater portion of their lengths for maintaining said blades in extended position.

and means whereby the pressure on the flushing water may be utilized for forcing the drill bit assembly into the chuck and for moving the wedge bars to their lower position.

22. A drilling apparatus comprising a drill stem casing, a chuck attached to said casing, a removable drill bit assembly adapted to be attached to said chuck including drill bits having cutting blades and a shank associated with and supporting each cutting blade, each blade having a rounded inclined shoulder adapted to engage a correspondingly shaped recess in the lower end of the chuck, a head, separate wedge bars carried by said head and movable along said shanks in contact therewith for forcing the cutting blades to an extended position on said chuck, said wedge bars contacting with said shanks throughout the greater portion of their-length for maintaining said blades in extended position, said inclined shoulders on the blades operating to force said blades inwardly when the wedge bars are removed and the bit assembly lifted relative to the chuck so as to permit the bit assembly to be withdrawn from the chuck, and means whereby pressure on the flushing water may be utilized for forcing the drill bit assembly into the chuck and for moving the Wedge bars to their lower position.

23. A drilling apparatus comprising a chuck, pipe sections attached thereto for rotating the chuck, a removable drill bit assembly adapted to be seated in said chuckl including drill bits, wedge bars adapted to be wedged between the bits and the wall of .the chuck for forcing the bits outwardly on the chuck, and means whereby iiuid pressure on the flushing water may be utilized for forcing the drill bit assembly into the chuck and for moving said Wedging bars for forcing the bits outwardly to extended position on said chuck and for maintaining said bits in extended position.

LELAND PAUL KINNEAR. 

